Bands with two or more canonical singers in different eras
I was listening to Marillion the other day and I started thinking about bands that have different eras with different singers and each of these eras have their fans. I guess there are loads of such bands when you started thinking about it.
Some that I can think of off the top of my head are:
Marillion (Fish and Steve Hogarth)
Fates Warning (John Arch and Ray Alder)
Black Sabbath (Ozzy and Dio)
Genesis (Peter Gabriel and Phil Collins)
Nightwish
These are interesting because the vocalist gives the voice to the band and in many cases, the sound changes drastically with the change of vocalist. Still, many bands manage to pull it off.
Dance Gavin Dance have had three "eras," though most fans seem to like all of them despite maybe having a favorite. They started with Johnny Craig on vocals for their first EP and record, then fired him and got Kurt Travis for two albums, then brought Johnny back for another album, then replaced him again with Tilian Pearson for the rest of their career to date (aside from a small tour where he was replaced by Andrew Wells due to a rehab stint.)
Malice Mizer.
The band had three different vocalists, and each time the music style and direction was different.
It went from Prog Goth rock (Tetsuo) to lighter Art / Synth Pop (Gackt), and then lastly dark metal (Klaha), all while maintaining its classical influence throughout.